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1� <br /> ASPHALT <br /> SPECIALTIES CO. <br /> Turnpike Mining Resource—Permit No.M-2004-009 November 25, 2019 <br /> Technical Revision No. 6(TR-06) Page 2 <br /> EXHIBIT C-2 MINE PLAN MAP—NORTH HALF OF PERMIT AREA (SHEET 1 OF 2) <br /> ■ The Hydraulic Barrier Trench cross-section for the Plumb and Dailey Ditch has been <br /> removed as installation of the trench is no longer applicable. <br /> ■ The approximate 1,400-foot x 220-foot strip of land along Plumb and Dailey Ditch to be <br /> mined and backfilled has been added to Cells 4 and 5. <br /> ■ An intermittent drainage which traverses the Site to Boulder Creek will be re-located by the <br /> Plumb and Dailey Ditch Company along the southern border of the area. <br /> EXHIBIT C-2 MINE PLAN MAP—SOUTH HALF OF PERMIT AREA (SHEET 2 OF 21 <br /> ■ No significant changes to map (included for completeness of Exhibit C-2). <br /> Copies of the Exhibit C-2—Mine Plan Maps are provided in Attachment A. <br /> 6.4.4. EXHIBIT D—MINING PLAN <br /> Other than minor changes to 6.4.4 (e) Approximate Mining Timetable, no significant changes will <br /> occur to the approved mining plan for the Site. The following subsections detail the specific <br /> information related to the partial mining of Cells 4 and 5 along the Plumb and Dailey Ditch covered <br /> in this TR-06. <br /> (a) Methods of Mining <br /> Overburden removal and mining will incorporate conventional aggregate mining methods, including <br /> use of scrapers to strip overburden, backhoes and scrapers to mine sand and gravel, and haul trucks <br /> to move material. The mining operation will be "dry"mined using temporary dewatering trenches at <br /> the toes of area slopes. <br /> (b) Earthmoving <br /> Overburden within the approximate 1,400-foot x 220-foot wide area will be stripped and temporarily <br /> stockpiled in Cell 4. Overburden includes topsoil as well as non-topsoil material which will be <br /> stockpiled separately from each other. In general, overburden west of Boulder Creek occurs at an <br /> average thickness of 5-feet below ground surface (bgs) and is composed of an average 0.5-feet of <br /> loam followed by silty and clayey sand to sandy and silty clay. The average thickness of the sand <br /> and gravel deposit is 10-feet. The sand and gravel deposits are underlain by shale. After mining is <br /> complete, the area will be backfilled with the stripped overburden material. <br /> (c) Water Diversions and Impoundments <br /> Temporary dewatering trenches will be dug around the perimeter of the mining area and water will <br /> be gravity fed into a dug sump for discharged to Boulder Creek (Outfall 002-A) via pump and <br /> above-ground piping. After mining is complete, the temporary dewatering trenches and sump will be <br />